Legacy Support in Windows 7
This paper speaks about Windows 7 that has been built to keep the security and reliability paramount. Applications not written for Windows Vista and above have a low chance of working with Windows 7. However, to ensure that this does not become a stumbling block, Microsoft has enabled certain SKUs of Windows 7 to get a Windows XP license to run in a virtual environment and give users access to applications installed in this Windows XP directly. This is done using the new version of Virtual PC now called Windows Virtual PC 7.